Drought may be causing higher rates of snakebites in Southern California

The Southern Pacific rattlesnake is the most common rattlesnake found in wild area in Southern California and one of the most deadly. This snake was just off the trail in Powder Canyon, near La Habra, part of the Puente Hills Habitat Preservation Authority. (photo by Terry Tuttle).

Snake Facts, tips

It is a myth that smaller rattlesnakes give more venom than adult snakes.

25 percent to 50 percent of rattlesnake bites are dry bites.

Never provoke a rattlesnake.

When hiking, wear sturdy shoes and loose-fitting pants. Stay on trails. Don’t put your hands on a rock where a snake can hide.

If bitten, call 9-1-1. Stay calm. Don’t use tourniquets or suck out the venom. Get to a hospital as soon as possible.

Never hike alone. Always carry a cellphone. Tell family members where you’re going ahead of time.

Treatment for a rattlesnake bite can require up to four of five days in a hospital.

The last person to die from a snakebite in Southern California was in 2010.

Sierra Madre Police Chief Larry Giannone stared down trouble last month during an encounter with a wild reptile, the Southern Pacific rattlesnake.

On May 14, a resident called 9-1-1 to report a rattlesnake outside her patio door. Giannone, recognizing the life-and-death situation such an animal can present, responded personally. He grabbed the sinewy reptile using a 3-foot metal tong, delicately placed it into a bucket and later released it into the Angeles National Forest at Chantry Flat.

For many leafy foothill communities where crime is low, law enforcement can come closer to danger from fugitive rattlesnakes than from violent criminals. “I’ve done this multiple times,” he said nonchalantly, but never more than this year.

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As Southern California suffers through the third year of drought, rattlesnakes are moving farther from their territory searching for food and water, many biologists report. This is worrisome to emergency room doctors who say the state is on pace for a record year of snakebites, often from vipers that pack a more deadly dose of venom than ever before.

“It is a serious thing,” Giannone said. “We have had more rattlesnake calls this year than in past years. Definitely more than usual.”

Ten days later, Giannone’s department received a call from a woman who was gardening and was bitten by a rattlesnake. Her arm quickly swelled to twice its size, he said. She was rushed to Arcadia Methodist Hospital and given doses of anti-venin and stayed at the hospital until she recovered, he said.

Sierra Madre, a quiet town in the shadow of the San Gabriel Mountains in northeastern Los Angeles County, has not had another bite since then, he said. “Let’s hope this is the last one,” said the chief.

Snake bites on the rise

Doctors with the California Poison Control System say that is not likely. The number of snakebite victims receiving anti-venin is nearing 100 in less than half a year, well ahead of pace of last year, said Dr. Stuart Heard, executive director of the CPCS.

As of June 12, 128 people were admitted to a hospital for a snakebite and of those, 93 received doses of anti-venin, Heard said. In 2013, 269 Californians went to a hospital for a snakebite and of those, 166 received anti-venin, he said. Simply doubling the number of patients needing anti-venin treatment would equal 186, more than 2013. (Some patients get “dry bites” meaning no venom is injected and therefore do not need anti-venin, he said).

Heard said doubling the numbers would not produce an accurate forecast — it would underestimate the total. This year, fires and early, warmer temperatures have awoken snakes from hibernation sooner than normal, sending them scattering for food, which could increase the likelihood of encounters with humans. With months of hot weather ahead, Heard is concerned the number of victims easily could rise above last year’s total.

“It potentially can be a very active snake season. We are at no less of a pace than last year and it can potentially be more, so we’ll have to keep an eye on it,” said Heard, who also is a professor at the UC San Francisco School of Pharmacy.

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Hospitals must report the use of anti-venin to the CPCS. But the system does not keep records on where the bites took place and the agency may not get notice of every bite, such as those treated elsewhere.

Snakebites in Southern California far outnumber those in Northern California, said Dr. Richard Clark, medical director of the San Diego division of the California Poison Control System and the director of toxicology at the UC San Diego Medical Center.

Snake bites are on the rise in San Diego and Southern California, he said, because the rash of wildfires in January, February, March and April have disturbed their habitat and driven rattlesnakes farther into areas where there are more people.

Clark, who runs experiments on the chemistry of snakebites, said snake venom appears to be getting more toxic, though his observations are not backed up by peer-reviewed data, he said.

“I can tell you we’ve seen some pretty bad bites in the last couple years. It could be luck. I don’t know if it is biologically mutated,” Clark said.

On Thursday, Fillmore Volunteer Fire Department Assistant Chief Bill Herrera was bitten by a rattlesnake while searching for a missing Arcadia firefighter who had gone camping in the Sespe Wilderness. Herrera received 52 vials of anti-venin, possibly a record, said Ventura County Sheriff’s Sgt. Eric Buschow.

The last death from a snakebite in California took place in 2010, Clark said.

Most common rattlers

Southern Pacific rattlesnakes are the most common species in Southern California. They are grey and black with a white rattle that warns humans to stay away. Other local rattlesnake varieties include: red diamondback, speckled rattlesnake, Mojave green, sidewinders and the western diamondback.

“Rattlesnakes are the most dangerous snakes in the world. They actually inject venom into you,” said Kevin Brennan, wildlife biologist with the California Department of Fish and Wildlife. “Other snakes may bite and it is a grinding bite. The rattlesnakes have hollow teeth with venom glands that act like a plunger in a hypodermic needle.”

Most snakes have hemotoxic venom, meaning the venom works on two parts of the blood: the platelets and the fibrinogen. By decreasing both, a patient can hemorrhage to death, Clark said.

Biologists and other observers say the San Jacinto Wilderness, part of the San Bernardino National Forest has experienced higher numbers of snakebites this season. In particular, the mountain community of Idyllwild is suffering from “snakebite paranoia,” said Brennan, an Idyllwild resident.

He’s seen more flyers posted around town this year warning residents to watch out for rattlesnakes. Dogs have been bitten this spring, leading to more veterinarians giving snakebite vaccines to man’s best friend, he said.

However, biologists in the Angeles National Forest and in the Santa Monica Mountains National Recreation Area west of the 405 Freeway report no unusual snake activity.

Katy Delaney, a wildlife ecologist with the U.S. National Park Service who studies reptiles and amphibians in the SMMNRA, said scarce water levels means low moisture content in plants; that attracts fewer rodents, squirrels and rabbits — less prey for snakes.

“In a drought, what has happened is there is less food for them (rattlesnakes) so they are roaming and moving around more,” Delaney said.

Brennan doesn’t believe snakes are affected by the drought because they’ve evolved in Southern California where droughts are frequent. Instead, rattlesnakes are more active as daylight hours lengthen. The sun signals their pituitary glands to wake up, get food and find a mate, he said.

Warm weather also brings snakes out of hibernation. They find a path or a piece of blacktop that has been heated by the sun to warm their cold-blooded bodies.

“It (rise in snakebites) has nothing to do with the drought. It is like real estate: location, location, location,” Brennan said. More people are out on forest trails in spring in summer as schools let out.

Whatever the reasons, biologists and doctors said agencies need to post more signs explaining how to prevent snakebites.

Too many people wear shorts and flip-flops instead of long, loose-fitting pants and boots or sturdy shoes, said biologists. Also, going off trail and being unable to hear a snake’s rattle because someone’s wearing earbuds with music blaring adds to the possibility of getting bitten, said Lizette Longacre, ecologist with the Puente Hills Habitat Preservation Authority.

“Sometimes, being able to hear what is around you is beneficial,” Longacre said.